Nuclear Magnetic Resonance (NMR) and, to a lesser degree, Electron Spin Resonance (ESR) are widely used in chemical analysis and medical diagnostics. NMR is a physical phenomenon that occurs when the nuclei of certain atoms that are subject to a static magnetic field are exposed to a second oscillating magnetic field. The oscillating magnetic field, often generated by an electromagnet, is also called a perturbing or excitation magnetic field. Some nuclei experience this phenomenon, and others do not, dependent upon whether they possess a property called spin. ESR, which is also called Electron Paramagnetic Resonance (EPR), is a physical phenomenon analogous to NMR, but instead of the spins of the atom's nuclei, electron spins are excited in an ESR. Because of the difference in mass between nuclei and electrons, weaker static magnetic fields and higher frequencies for the oscillating magnetic fields are used, compared to NMR.
The current devices using the NMR or ESR principle have at least two drawbacks. First, the sizes of the devices are too big. For example, typical NMR spectrometers are bench-top models. Thus, the current spectrometers are too big to be used in field applications or at home environment. Second, the current NMR devices require a large amount of sample, which not only is infeasible for certain applications, but also hinders activities such as mixing and heating of the sample required for many analysis. Thus, there is a need for a miniaturized, integrated, and versatile NMR or ESR device that can perform on-site, flexible, rapid, sensitive, and/or efficient analysis.